聚酰亚胺LB膜研究：Ⅱ.聚酰胺酸N,N—二甲基十八铵盐LB膜的表征 …

聚酰胺酸Ｎ,Ｎ－二甲基十八铵盐ＬＢ膜具有严格排列的周期结构,其亚胺化可以在比聚酰胺酸更为温和的条件下进行。测定了沉积在单晶硅片上的聚酰亚胺涂膜的热分解性能。于真空和高温下聚酰亚胺ＬＢ膜会热解并与基片硅反应而生成规则结构的ＳｉＣ准单晶膜。     

聚酰亚胺LB膜研究 Ⅱ.聚酰胺酸N,N-二甲基十八铵盐LB膜的表征和热分解性能

聚酰胺酸Ｎ,Ｎ－二甲基十八铵盐ＬＢ膜具有严格排列的周期结构,其亚胺化可以在比聚酰胺酸更为温和的条件下进行。测定了沉积在单晶硅片上的聚酰亚胺涂膜的热分解性能。于真空和高温下聚酰亚胺ＬＢ膜会热解并与基片硅反应而生成规则结构的ＳｉＣ准单晶膜。     

聚酰亚胺模型化合物的结构模拟

聚酰亚胺模型化合物的结构模拟朱英史桂珍陆天虹＊（中国科学院长春应用化学研究所长春１３００２２）关键词聚酰亚胺，模型化合物，结构模拟，ＬＢ膜，半经验分子轨道计算方法１９９７－０９－３０收稿，１９９８－０１－０７修回金属腐蚀和防腐国家实验室资助项目近年来...     

聚酰亚胺LB膜研究进展

聚酰亚胺（ＰＩ）是一种高性能聚合物材料，通过Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜（ＬＢ膜）技术实现ＰＩ分子排列的有序化，可以使ＰＩ的某些性能更充分体出现来，详细总结了ＰＩＬＢ膜的制备方法，对其在气体分离，光敏性，液晶取向，介电以及光电导等方面性质的研究现状进行了较为全面的综合，对ＰＩＬＢ的研究和应用前景作了简要展望。     

有机HTDIOO分子LB膜结构的AFM研究

利用原子力显微镜（ＡＦＭ）对有机分子ＨＴＤＩＯＯ单层和多层ＬＢ膜结构进行了观察。实验结果表明，针尖与ＬＢ膜表面分子间的相互作用力会对成像的膜结构有影响。当悬臂针尖与ＬＢ膜表面分子的相互作用力较大时，针尖会扰动ＨＴＤＩＯＯ分子在单层ＬＢ膜中的有序排列。ＨＴＤＩＯＯ单层ＬＢ膜具有有序结构；而在多层ＬＢ膜中，ＨＴＤＩＯＯ分子则聚集在一起形成了一定的畴结构。     

倒浮萍聚合物LB膜的有序－无序相变研究

倒浮萍聚合物ＬＢ膜的有序－无序相变研究李宏斌，张希，张瑞丰，赵冰，徐尉青，沈家骢，高忠民（吉林大学分子光谱与分子结构开放实验室、化学系，分析测试中心，长春，１３００２３）关键词聚合物ＬＢ膜，有序－无序相变，变温红外光谱，变温小角Ｘ光衍射ＬＢ膜的有序－...     

含光功能基团聚合物LB膜的研究进展

本文在简要介绍含光功能基团聚合物ＬＢ膜之后，详细回顾了功能化ＬＢ膜体系光物理过程的研究，总结了含非线性光学基团聚合物ＬＢ膜的研究现状。最后，简要介绍了它们的应用前景。     

花生酸LB膜周期结构的环境稳定性

花生酸ＬＢ膜周期结构的环境稳定性何平笙，管水云，李春娥（中国科学技术大学材料科学与工程系，合肥，２３００２６）关键词Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜，Ｘ射线衍射，氨和ＨＣｌ溶液蒸汽处理，花生酸铅、镉、钡Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜（ＬＢ膜...     

酞菁铜与四氰代二甲基苯醌电荷转移反应的测定

用红外光谱、紫外可见光谱、循环伏安法等研究了三．（２，４－二特戊基苯氧基）－８－喹淋氧基酞菁铜（简称酞菁铜）和２－十八烷基－７，７，８，８－四氰二甲基苯醌（简称Ｃ１８－ＴＣＮＱ）在Ｌａｎｇ－ｍｕｉｒ－Ｂｌｏｄｇｅｔｔ（ＬＢ）膜中的电荷转移。实验结果表明，在交替和混合ＬＢ膜中，酞菁铜和Ｃ１８－ＴＣ－ＮＱ分子之间均发生了电荷转移，其中酞菁铜为给体分子，ＴＣＮＱ为受体分子。在混合ＬＢ膜中，电荷转移程度较大。电导率测量表明荷移反应使ＬＢ膜的电导率较纯酞菁铜ＬＢ膜提高了３个数量级。     

自组装膜修饰悬汞电极的制备及电化学特性

电子跨膜传递一直是生物能学的中心问题 ,长期以来生物学家和化学家一直为能在分子水平上研究生物膜上电子传递过程的模型体系而不懈努力．提出的模型体系有平板双分子层膜（ｐｌａｎｎｅｒｂｉｌａｙｅｒｌｉｐｉｄｍｅｍｂｒａｎｅ,ＢＬＭ）［１］、泡囊［２］、和固体支撑双分子层膜（ｓｏｌｉｄｓｕｐｐｏｒｔｅｄｂｉｌａｙｅｒｌｉｐｉｄｍｅｍｂｒａｎｅ ,Ｓ ＢＬＭ）［３］等 ,ＢＬＭ膜与实际生物膜最为相似 ,但极不稳定 ;Ｓ ＢＬＭ膜稳定性好 ,但基底不平 ,缺陷大 ,研究电子跨膜传递困难．而８０年代初 ,自组装(Ｓｅｌｆ Ａｓｓｅ…     

Investigation of alignment mechanism of liquid crystal on polyimide Langmuir-Blodgett films by scanning tunnelling microscopy

The homogeneous alignment of a liquid crystal material, 4'-n-octyl-4-cyanobiphenyl (8CB), was achieved by polyimide Langmuir-Blodgett (LB) films. Scanning electron microscopy and scanning tunnelling microscopy measurements show that the alignment of the polyimide LB films with a grooveless surface occurs due to the orientation of the polyimide chains. We directly observe 8CB monolayers on oriented polyimide LB films. We find that the monolayers form a two dimensional crystalline structure and the 8CB molecules are always aligned along the chain direction of the polyimide. The results show that the alignment of 8CB molecules arises by an epitaxial growth on the oriented polyimide LB films.     

Investigation of alignment mechanism of liquid crystal on polyimide Langmuir-Blodgett films by scanning tunnelling microscopy

Abstract

The homogeneous alignment of a liquid crystal material, 4′-n-octyl-4-cyanobiphenyl (8CB), was achieved by polyimide Langmuir-Blodgett (LB) films. Scanning electron microscopy and scanning tunnelling microscopy measurements show that the alignment of the polyimide LB films with a grooveless surface occurs due to the orientation of the polyimide chains. We directly observe 8CB monolayers on oriented polyimide LB films. We find that the monolayers form a two dimensional crystalline structure and the 8CB molecules are always aligned along the chain direction of the polyimide. The results show that the alignment of 8CB molecules arises by an epitaxial growth on the oriented polyimide LB films.     

聚酰亚胺LB膜热解制备SiC薄膜的XPS研究

用XPS对沉积在硅基片上的聚酰亚胺LB膜以及由它真空热解制备的SiC薄膜进行了研究 ,并对其形成过程进行了跟踪分析 .XPS结果显示聚酰亚胺LB膜结构均匀 ,质量良好 ;真空热解时 ,约在 6 70℃时LB膜中的C与衬底Si反应形成SiC ;Ar离子溅射深度俄歇谱表明所制备的SiC膜中Si和C浓度成梯度分布 ,说明SiC是由Si和C相互扩散反应形成的     

Spectroscopic and optical characterization of porphyrin chromophores incorporated into ultrathin polyimide films

Polyamic acid (PAA) containing free-base porphyrin and zinc(II) porphyrin chromophores was synthesized by copolymerization of diphenylether-type tetracarboxylic dianhydride and diamines. The monolayer of the alkylamine salts of PAA (PAASs) at the air/water interface was deposited on solid substrates by the Langmuir-Blodgett (LB) technique. The PAAS LB films thus obtained were converted to polyimide (PI) LB films by chemical treatment. The fluorescence of porphyrin moieties in the PI LB film was observed, because of the weak electron-accepting properties of the diphenylether unit. Therefore, the photophysically important processes, such as photoinduced electron transfer, excitation energy transfer, and excitation energy migration could be investigated in relation to the layered nanostructures of the ultrathin PI films. The fluorescence spectrum suggested that the aggregation of porphyrin moieties in the PI LB films was effectively prevented by the use of polymeric films. The surface plasmon (SP) measurement showed that the thickness of the monolayers was 0.9-1.0 nm for PAAS films and 0.32-0.40 nm on average for PI LB films. The absorption dichroism of the Soret band of porphyrin indicated that porphyrin moieties in the PAAS and PI LB films are oriented in parallel with the substrate. These results showed that the orientation and the spatial distribution of porphyrin units can be efficiently regulated in the PI LB films in a nanometer dimension.     

聚酰亚胺LB膜真空热解制备β-SiC膜的STM观察

扫描隧道显微镜 ( STM)是一种基于量子隧道效应对样品进行高分辨无损测试的表面测试技术 [1] ,它可以在原子水平上反映表面分子或原子的排列分布情况 ,在物理、化学、生物和微电子界受到高度的重视 .STM技术以及其后发展起来的原子力显微镜 ( AFM)特别适合 LB膜的研究 ,能直观地反映出 LB膜中分子排列的微观结构以及表面缺陷 [2 ,3] .我们曾通过真空热解沉积在单晶硅片上的聚酰亚胺L B膜制得了准单晶β- Si C超薄膜 [4～ 6 ] .本文利用 STM技术对聚酰亚胺 LB膜以及由它真空热解而成的 Si C膜的表面形态结构进行了初步观察和分析 .…     

聚合物的LB膜

简要介绍了聚合物LB(Langmuir -Blodgett)膜的制备装置和制备过程。同时对聚合物LB膜这一门学科最新的进展和应用前景做了较为详尽的介绍和论述。目前 ,随着对LB膜的研究深入 ,在对小分子LB膜、可聚合LB膜、聚合物LB膜的成膜研究中引入了将几种方法优点综合起来的新的成膜方法 ,并已成为研究热点     

聚苯胺基LB膜的制备及气敏特性的研究

以聚苯胺 (PAN)为原料 ,利用LB(Langmuir Blodgett)超薄分子膜技术 ,制备了不同层数的纯聚苯胺LB膜及聚苯胺与乙酸 (AA)混合 (PAN AA)LB膜 ,对其进行了紫外 可见光光谱分析研究 ,并对不同层数的聚苯胺基LB膜的二氧化氮 (NO2 )气敏特性进行了研究 ,发现PANLB膜较PAN AALB膜具有更好的敏感性、响应性和可逆性 ,3层和 15层PANLB膜对相对百分比为 2 0× 10 -6NO2 的响应时间分别为 10s和 30s,15层PANLB膜的恢复时间约为 4min     

Mechanical properties degradation of polyimide films irradiated by atomic oxygen

Mechanical properties of polyimide films are degraded by exposure to a low earth orbit environment. The main environmental factor for that degradation is atomic oxygen (AO). Using tensile tests, AO-irradiated surface topography observations, and fracture surface analyses, this study investigated the degradation behavior of polyimide films’ mechanical properties by increased AO fluence and its accompanying degradation mechanisms. Tensile strength and elongation of polyimide films were reduced concomitantly with increased AO fluence. Furthermore, AO-irradiated polyimide films fractured from the AO-irradiated surfaces, of which roughness became marked as AO fluence increased. These results reflect that reduction of mechanical properties is attributable to the roughness increase in AO-irradiated surfaces. Polyimide films coated with indium tin oxide (ITO) were also evaluated to confirm the degradation behavior of AO protective films. Surfaces of ITO-coated polyimide films remained smooth even after AO irradiation. However, undercut cavities were formed at ITO coating defect sites. Rupture of ITO-coated polyimide films initiates from the undercut cavities, engendering large reduction of tensile strength and elongation. The degradation of the mechanical properties of ITO-coated polyimide films increased substantially until the undercut cavities fully penetrated the film.     

Langmuir-Blodgett films of p-terphenyl in different matrices: evidence of dual excimer

Langmuir-Blodgett (LB) films at different mole fractions of p-terphenyl have been prepared using two different matrices, viz., stearic acid (SA) and polymethyl methacrylate (PMMA). Multilayered LB films have been formed by changing various LB parameters namely, mole fraction of mixing, changing the number of layers as well as also the different surface pressure of lifting. The spectroscopic characteristics of mixed LB films, solution and microcrystal have been compared using UV-vis absorption and steady state fluorescence spectroscopy. Change of planarity of TP molecules are occurred while going from solution to solid states/films. Fluorescence spectra of the mixed LB films reveal intense excimeric emission in the mixed LB films with D1 excimer peak at 397 nm and D2 excimer peak at 412 nm. Various LB parameters namely changing the number of layers as well as the different surface pressure of lifting played important roles in the formation of dual excimeric sites in the mixed LB films.     

非典型双亲性β-二酮稀土配合物LB膜荧光稳定性 的研究

研究了一系列非典型双亲性β-二酮稀土配合物LB膜在紫外光激发下两种不同条件时的荧光稳定性：(1)每40s检测一次;(2)每周检测一次。第一种条件下,稀土配合物LB膜的荧光强度以直线关系缓慢衰减,30次后变化约4%。第二种条件下荧光强度呈单指数关系衰减。荧光强度衰减至原始值的1/e时间τ约为10周{如n[Eu·(TTA~3)Phen]:n(AA)=1:1LB的τ为11.4周}。相同激发次数(大于1次)时,第二种条件比第一种条件下LB膜荧光强度小。紫外可见吸收光谱结果表明,受紫外光激发后,LB膜中稀土配合物的吸光度降低且随时间延长吸光度进一步降低,导致荧光发射强度减小。放置半年后LB膜的光强度仍可被检测到。低角度X衍射结果表明,LB膜具有良好的周期性层状结构且层状结构可长时间稳定存在,有利于提高稀土配合物LB膜的荧光稳定性。